The subject matter of this invention is a swivel coupling for connecting a hose containing a plurality of conduits to a handpiece such as a dental handpiece having like conduits. More specifically, the swivel coupling of this invention connects a hose containing conduits for drive air, secondary air, water, and light to a dental handpiece having like conduits for drive air to drive a turbine motor, secondary air or chip air for scavenging a work area, water for washing and cooling the work area, and optical fibers for illuminating the work area.
The most relevant prior art I know of is U.S. Pat. No. 4,431,412 issued Feb. 14, 1984 to Joseph and Albert Lares. The Lares patent discloses a dental handpiece with swivel coupling for transmitting air, water and light. As will be readily appreciated from FIGS. 3-6 of the Lares patent, the several passages for drive air, secondary air, water and light are arranged in discrete, non-contiguous positions within a cylindrical spool member. The light conductor passes through the center passage and the other passages are arranged around it, exiting the spool radially at points spaced longitudinally along it.
The present invention makes more efficient use of space within the swivel coupling.
The present invention may be summarized as a swivel coupling for transmitting drive air, secondary air, water and light. A hose containing separate conduits for all these media is threaded to one end of the coupling, a handpiece having like conduits is threaded to the other end, and the two ends or halves of the coupling are rotatably connected to each other. Within the coupling is a spool or cartridge including an outer casing and a concentric inner tube for an optical fiber bundle, the space between casing tube defining arcuate passages for drive air, secondary air, and water. These several passages communicate with corresponding passages in the handpiece and in the hose end of the coupling for unlimited swivel capability.